Chapter 31: Male Reproductive System

Question 1

Objectives:

Identify key components of the male and female reproductive systems.

Answer 1

fyi

Question 2

• Functioning of the reproductive system ensures the survival of the genetic characteristics of a species
• Depends on union of male and female gametes (sex cells)
• Each gamete has a half set of chromosomes
• Male and female reproductive systems designed to enable union of genetic material

Answer 2

SEXUAL REPRODUCTION

Question 3

this system consists of organs whose functions are to produce, transfer, and introduce mature sperm into the female reproductive tract, where fertilization can occur

Answer 3

Male Reproductive System

Question 4

theses organs are for production of gametes or accessory organs that support the reproductive process (Figure 31-1)

Essential organs

Answer 4

gonads of the male; testes

Question 5

Genital ducts convey sperm outside the body. These include a pair of epididymides, paired vasa deferentia (vas deferens), pair of ejaculatory ducts, and the urethra
Accessory glands produce secretions that nourish, transport, and mature sperm. These include a pair of seminal vesicles, the prostate, and pair of bulbourethral glands.
Supporting structures: scrotum, penis, and pair of spermatic cords

Answer 5

Accessory organs of reproduction

Question 6

Genital ducts convey sperm outside the body. These include 3 paired organs a one single.

Answer 6

epididymides

vasa deferentia (vas deferens)

**ejaculatory ducts **

urethra

Question 7

Accessory glands produce secretions that nourish, transport, and mature sperm. These include

Answer 7

a pair of seminal vesicles

the prostate

pair of bulbourethral glands.

Question 8

MALE REPRODUCTIVE ORGANS

Supporting structures:

Answer 8

• scrotum
• **penis **
• pair of spermatic cords

Question 9

• Located in the scrotum, one testis in each of two scrotal compartments
• Several lobules composed of 1-3 seminiferous tubules and interstitial cells (Leydig cells), separated by septa and encased in fibrous capsule called the tunica albuginea (Figure 31-3)
• Seminiferous tubules in testis open into a plexus called rete testis, which is drained by a series of efferent ductules that emerge from the top of the organ and enter the head of epididymis

Answer 9

TESTES - Structure and Location


Question 10

endocrine cells between the seminiferous tubules; secrete testosterone

Answer 10

Interstitial (Leydig) cells

part of the

Microscopic anatomy (Figures 31-4 to 31-6)

Question 11

Spermatogenic cells produce ?

Answer 11

sperm or spermatozoa

Question 12

• Support and regulate sperm-producing functions of the testis
• Help to increase testosterone in the seminiferous tubules
• Tight junctions between these cells form the blood-testis barrier, which protects developing sperm from the immune system

Answer 12

Sustentacular cells: also called nurse or Sertoli cells

part of the

Microscopic anatomy (Figures 31-4 to 31-6)

Question 13

thses are functions of what?

• Spermatogenesis:
• Secretion of hormones (Figure 31-7)

Answer 13

TESTES

Question 14

formation of mature male gametes (spermatozoa) by seminiferous tubules

Answer 14

Spermatogenesis

Question 15

Spermatogenisis is stimulated by __________ -_________ ___________ from the anterior pituitary (and also gonadotropin-releasing hormone from hypothalamus)

Answer 15

follicle-stimulating hormone

Question 16

• Type of androgen: masculinizing hormone
• Stimulates spermatogenesis
• Stimulates primary and secondary sexual characteristics
• Promotes growth of muscle and bone

Answer 16

Testosterone

(produced by interstitial cells)

Question 17

inhibits release of follicle-stimulating hormone (stimulates spermatogenesis) by anterior pituitary and therefore indirectly decreases sperm production

Answer 17

Inhibin

(produced by sustentacular cells)

Question 18

Structure of spermatozoa: consists of

Answer 18

• head (covered by acrosome)
• neck
• midpiece
• tail

Question 19

The head of the spermatozoa contains a highly compact package of …..?

Answer 19

genetic chromatin

Question 20

The ____________ contains enzymes that assist the sperm in breaking through the cervical mucus and the ovum

Answer 20

acrosome

Question 21

The midpiece contains____________

Answer 21

** mitochondria**

Question 22

Structure and location of what?

• Single tightly coiled tube enclosed in fibrous casing (Figure 31-9)
• Lies along top and side of each testis
• Anatomical divisions include head, body, and tail

Answer 22

Epididymis

Question 23

Functions of what?

• Duct through which sperm pass and mature (1-3 weeks)
• Secretions become part of seminal fluid
• Sperm become capable of motility while they are passing through this

Answer 23

Epididymis

Question 24

Structure and location of what?

• Tube, extension of epididymis
• Extends through inguinal canal, into abdominal cavity, over top and down posterior surface of bladder
• Has a thick mm wall that helps to propel sperm
• Enlarged terminal portion called ampulla joins the duct of the seminal vesicle

Answer 24

Vas deferens (ductus deferens)

(Figures 31-10 and 31-11)

Question 25

Function of what? * Excretory duct for seminal fluid * Connects epididymis with the ejaculatory duct

Answer 25

Vas deferens (ductus deferens) | (Figures 31-10 and 31-11)

Question 26

Vasectomy is referring to

Answer 26

Vas deferens

Question 27

* **Formed by union of vas deferens with duct from seminal vesicle** * **Passes through prostate gland, terminating in urethra**

Answer 27

Ejaculatory duct (Figure 31-12)

Question 28

**Serves both the reproductive and the urinary systems**

Answer 28

**Urethra**

Question 29

Structure and location of what? convoluted pouches 5 to 7 cm long on posterior surface of bladder

Answer 29

Seminal vesicles (Figure 31-13)

Question 30

Function of what? **secrete the viscous, nutrient-rich part of seminal fluid (60% of semen volume) which provides the sperm with energy and helps adjust the pH of the vagina**

Answer 30

Seminal vesicles (Figure 31-13)

Question 31

Structure and location of what? * Doughnut shaped * Encircles urethra just below bladder

Answer 31

Prostate gland (Figure 31-14)

Question 32

Function of what? **adds slightly acidic, watery, milky-looking secretion to seminal fluid (30% of semen volume) which provides nutrients and enzymes for the sperm**

Answer 32

Prostate gland (Figure 31-14)

Question 33

Structure and location of what? * Small, pea-shaped structures with approximately 2.5-cm long (1 inch) ducts leading into urethra * Lie below prostate gland

Answer 33

Bulbourethral glands

Question 34

Function of what? **secrete alkaline fluid that is part of semen (5% of semen volume) which again helps to adjust the vaginal pH**

Answer 34

Bulbourethral glands

Question 35

* Skin-covered pouch suspended from perineal region into which the testes descend near the time of birth (Figure 31-11) * Divided into two compartments * **Contains testis, epididymis, and lower part of a spermatic cord** * **Dartos and cremaster muscles elevate the scrotal pouch**

Answer 35

Scrotum

Question 36

Structure of what? composed of three cylindrical masses of erectile tissue, one of which contains urethra

Answer 36

Penis (Figure 31-14)

Question 37

Functions of what? **this contains the urethra, the terminal duct for both urinary and reproductive tracts; during sexual arousal, it becomes erect, serving as a penetrating organ during sexual intercourse**

Answer 37

Penis (Figure 31-14)

Question 38

* Fibrous cylinders located in inguinal canals * **Enclose seminal ducts, blood vessels, lymphatics, and nerves**

Answer 38

Spermatic cords (internal)

Question 39

COMPOSITION AND COURSE OF SEMINAL FLUID

Answer 39

* Consists of secretions from testes, epididymides, seminal vesicles, prostate, and bulbourethral glands * Each milliliter contains millions of sperm * Spermatozoa Pathway: Passes from Seminiferous tubule of the testes epididymis, vas deferens, ejaculatory duct, and urethra

Question 40

COMPOSITION AND COURSE OF SEMINAL FLUID Consists of secretions from?

Answer 40

* testes, * epididymides, * seminal vesicles, * prostate, * bulbourethral glands

Question 41

Passes from Seminiferous tubule of the testes epididymis, vas deferens, ejaculatory duct, and urethra

Answer 41

**Spermatozoa Pathway**

Question 42

* Relates to many factors: number, size, shape, and motility of sperm * Infertility may be caused by antibodies some men make against their own sperm * For Males this begins at puberty and extends into old age (Figure 31-15)

Answer 42

MALE FERTILITY

Question 43

CYCLE OF LIFE: MALE REPRODUCTIVE SYSTEM

Answer 43

* Reproductive functions begin at time of puberty * Development of organs begins before birth; immature testes descend into scrotum before or shortly after birth (Figure 31-16) * Puberty: high levels of hormones stimulate final stages of development * System operates to permit reproduction until advanced old age * Late adulthood: gradual decline in hormone production may decrease sexual appetite and fertility